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Relation Analysis Among Academic Research Areas Using Subject Terms of Domestic Journal Papers (국내 학술지 논문의 주제어를 통한 학술연구분야 관계분석)

  • Lee, Hye-Young;Kwak, Seung-Jin
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.22 no.3
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    • pp.353-371
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    • 2011
  • The purpose of this paper is to analyze the interrelation among research areas based on domestic journal papers, achievements of korea researchers. Generally, the content of papers is appeared through abstracts, subjects, full-text and so on. This paper is focused on subject terms of Domestic journal papers. The experimental data are 80 domestic journals, 7,616 papers and 58,143 subject terms and papers published in 2009. As the result, it was different to use subject terms on each research area: Engineering, Agriculture & Oceanography, Interdisciplinary Science, Social Science, Arts & Physical Education, Medicine & Pharmacology, Humanities and Natural Science. Subject terms of Engineering have used the most in the other research areas in aspect of term co-occurrence. The 8 research areas were grouped in 3 clusters: C1(Engineering, Natural Science, Social Science, Interdisciplinary Science, Humanities), C2(Medicine & Pharmacology, Arts & Physical Education), and C3(Agriculture & Oceanography).

Depth-based Correction of Side Scan Sonal Image Data and Segmentation for Seafloor Classification (수심을 고려한 사이드 스캔 소나 자료의 보정 및 해저면 분류를 위한 영상분할)

  • 서상일;김학일;이광훈;김대철
    • Korean Journal of Remote Sensing
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    • v.13 no.2
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    • pp.133-150
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    • 1997
  • The purpose of this paper is to develop an algorithm of classification and interpretation of seafloor based on side scan sonar data. The algorithm consists of mosaicking of sonar data using navigation data, correction and compensation of the acouctic amplitude data considering the charateristics of the side scan sonar system, and segmentation of the seafloor using digital image processing techniques. The correction and compensation process is essential because there is usually difference in acoustic amplitudes from the same distance of the port-side and the starboard-side and the amplitudes become attenuated as the distance is increasing. In this paper, proposed is an algorithm of compensating the side scan sonar data, and its result is compared with the mosaicking result without any compensation. The algorithm considers the amplitude characteristics according to the tow-fish's depth as well as the attenuation trend of the side scan sonar along the beam positions. This paper also proposes an image segmentation algorithm based on the texture, where the criterion is the maximum occurence related with gray level. The preliminary experiment has been carried out with the side scan sonar data and its result is demonstrated.

Spectroscopic Studies on the High-$T_c$ Superconducting $La_2CuO_{4-δ}$ Prepared by Electrochemical Oxidation

  • 박정철;Alain Wattiaux;Jean-Claude Grenier;김동훈;최진호
    • Bulletin of the Korean Chemical Society
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    • v.18 no.9
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    • pp.916-922
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    • 1997
  • A superconducting phase La2CuO4+δ (Tc=44 K) has been prepared by electrochemical oxidation which allows the oxygen to intercalat into the La2O2 layers. According to the Cu K-edge X-ray absorption near edge structure spectroscopic analysis, the oxidized phase shows an overall spectra shift of about 0.5 eV to a higher energy region compared to the as sintered one with the occurrence of an additional peak corresponding to the transition to the |1s13dn+1L-14pσ1 > final state, indicating the oxidation of CuO2 layer. From the X-ray photoelectron spectroscopic studies, it is found that the binding energy of La 3d5/2 is significantly shifted from 834.3 eV (as sintered La2CuO4) to 833.6 eV (as electrochemically oxidized La2CuO4+δ), implying that the covalency of the (La-O) bond is decreased due to the oxygen intercalation. The O 1s spectra do not provide an evidence of the superoxide or peroxide, but the oxide (O2-) with the contaminated carbonate (CO32-) based on the peaks at 529 eV and 532 eV, respectively, which is clearly confirmed by the Auger spectroscopic analysis. Oxygen contents determined by iodometric titration (δ=0.07) and thermogravimetry (δ=0.09) show good coincidence each other, also giving an evidence for the "O2-" nature of excess oxygen. From the above results, it is concluded that "O2-" appeared as O 1s peak at 528.6 eV is responsible for superconductivity of La2CuO4+δ.

Camera Model Identification Based on Deep Learning (딥러닝 기반 카메라 모델 판별)

  • Lee, Soo Hyeon;Kim, Dong Hyun;Lee, Hae-Yeoun
    • KIPS Transactions on Software and Data Engineering
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    • v.8 no.10
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    • pp.411-420
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    • 2019
  • Camera model identification has been a subject of steady study in the field of digital forensics. Among the increasingly sophisticated crimes, crimes such as illegal filming are taking up a high number of crimes because they are hard to detect as cameras become smaller. Therefore, technology that can specify which camera a particular image was taken on could be used as evidence to prove a criminal's suspicion when a criminal denies his or her criminal behavior. This paper proposes a deep learning model to identify the camera model used to acquire the image. The proposed model consists of four convolution layers and two fully connection layers, and a high pass filter is used as a filter for data pre-processing. To verify the performance of the proposed model, Dresden Image Database was used and the dataset was generated by applying the sequential partition method. To show the performance of the proposed model, it is compared with existing studies using 3 layers model or model with GLCM. The proposed model achieves 98% accuracy which is similar to that of the latest technology.

Case Studies of Ground Subsidence Risk Ratings (GSRp) Applied to the Excavation Sites (지반함몰 위험등급 분류(GSRp)의 굴착현장 사례 연구)

  • Shin, Sang-Sik;Ihm, Myeong-Hyek;Kim, Hak Joon
    • The Journal of Engineering Geology
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    • v.29 no.3
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    • pp.289-302
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    • 2019
  • As the occurrence of ground subsidence near the excavation site increases recently, studies are being conducted to predict the possibility of ground subsidence prior to excavation. In this study, the ground subsidence risk rating for pre-excavation (GSRp) developed by the previous study was applied to actual excavation sites to verify its applicability. The final results for the evaluation of the ground subsidence risk level for five excavation sites revealed that GSRp scores were calculated between 40 and 79 points and classified mainly into grades II (Good Ground)~III (Fair Ground). In order to verify the evaluation method, the obtained GSRp grades were compared with the measured horizontal displacements. The horizontal displacements measured in five excavation sites were between 25% and 47% of the allowable displacement, which were well agreed with the low subsidence risk level obtained from GSRp calculation. It is expected that the GSRp method can be used as an evaluation tool for predicting the risk of ground subsidence before excavation if GSRp is verified and supplemented through the additional research for the poor soil with the high risk of ground subsidence.

Implosion Analysis of Circular Cylinder using Simplified Model (간이물리모델을 이용한 원통형 압력용기의 내파해석)

  • Nho, In Sik;Cho, Sang Rai;Kim, Yong Yook;Han, Soonhung;Cho, Yoon Sik
    • Journal of the Society of Naval Architects of Korea
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    • v.57 no.1
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    • pp.8-14
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    • 2020
  • The implosion phenomena of pressure vessels operating in deep water under extremely high external pressure have been well known. The drastic energy release to ambient field in the form of pressure pulse is accompanied with catastrophic collapse of shell structure. Such a proximity shock wave could be a serious threat to the structural integrity of adjacent submerged body and several suspected accidents have been reported. In this study, basic research for the occurrence and development of shock wave due to implosion was carried out. The mechanism of pressure pulse generation and energy dissipation were investigated, and a simplified kinematic model to approximate the collapse modes of circular tubes which can be generated by external pressure and implosion was examined. Using the simplified kinematic model, the process of energy dissipation was formulated, and the magnitude of released pressure shock wave was estimated quantitatively. To investigate the validity of developed kinematic model and shock wave estimation process, the results from a nonlinear FE analysis code and collapse test carried out using pressure chamber were compared with the results from the developed kinematic model.

A Study on the Fluid Flow According to the Opening Angle of a Butterfly Valve with High Control Performance (고제어 성능을 가진 버터플라이밸브의 개도각에 따른 유체유동에 대한 연구)

  • Yu, Seong-Hun;Park, Sang-Hee;Hwang, Jeong-Gyu;Yang, Hee-Jo
    • Journal of the Korean Society of Industry Convergence
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    • v.24 no.5
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    • pp.617-623
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    • 2021
  • The objective of this study is to simulate valve flow coefficient and flow characteristics such as velocity and pressure distribution for butterfly valve. The size of the valve used in this study is 125A. The range of the valve opening angle was α=15°~70°, and it was changed by 5°. At the range of α=15°~30°, the valve flow coefficient K𝜐 gradually increased, and after α=30°, it increased rapidly. In the range of α=20°~70°, the pressure change in the -2.9cm~+2.9cm region in the pipe greatly depended on the opening angle and the position within the pipe. However, after +2.9cm, the pressure at the rear end of the valve was shown to depend only on the opening angle. At α=20°, Vortex shedding occurred for the first time at time t=0.25sec and continuously occurred in rear end of the valve over time. After α=45°, in the flow pattern at the rear end of the valve, the upward flow at the lower end of the valve and the flow at the upper end met each other to form a mixed flow. This flow phenomenon was shown to form a more intense mixed flow in the rear end region as the opening angle increased. Vortex flow occurred for the first time at α=15°, and the opening angle increased, the occurrence and disappearance of this flow phenomenon occurred periodically according to the certain flow region. The pattern of the pressure distribution in the region at the rear end of the valve showed a tendency to agree well with the results of the vorticity distribution.

Development of a Manual for Simulation Training in Preparation for the Fall Disasters of Urban Residential Housing Construction Works and Apply (도시형 생활주택신축공사의 추락재해 발생대비 모의훈련 실시 매뉴얼 개발 및 적용)

  • Kim, Sung Soo
    • Journal of Korean Society of Disaster and Security
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    • v.14 no.3
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    • pp.39-49
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    • 2021
  • According to the recent "Status of Industrial Accidents at the End of December 2020" released by the Ministry of Employment and Labor, each industry is subject to industrial accidents. The number of accident deaths by construction industry, accident deaths by accident type fell, and accident deaths by workplace size were 5 to 49, indicating that most accident deaths occurred due to falling accidents at small construction sites. Therefore, urban living houses are small construction sites, and the probability of falling accidents is very high. Fall simulation training for disaster occurrence is conducted mainly by large construction ordering organizations in the public sector, and it is the first case in Korea that a housing construction company has conducted at a small construction site. This study analyzed and presented the definition, construction characteristics, and safety management status of urban living houses, and developed and spread an emergency relief procedure manual in the event of a fall accident to minimize deaths.

Analysis on Topics of Digital Preservation Researches and Courses (디지털 보존 관련 학술연구 및 교과 주제분석)

  • Jeong, Uiyeon;Choi, Sanghee
    • Journal of the Korean Society for Library and Information Science
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    • v.53 no.3
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    • pp.25-43
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    • 2019
  • Recently there has been a growing interest in digital preservation and digital curation with rapid increase of digital resource. This study aims to investigate the research topics and the course topics related digital preservation and digital curation. The course information is collected from the curricular of library and information science departments and archival science departments in leading countries such as US, England, Ireland, Canada and New Zealand. Title keyword profiling and network analysis were adapted to discover core research and education areas. The key topics in the abstracts of research papers and the contents of the course were also illustrated by these methods. In the research analysis, archival system is the biggest area of researches related digital preservation and digital curation. Courser analysis shows digital curation education and process is the important area of education. As a result of content analysis, plan and strategy is a notable topic of research and record management process is a major topic of courses for digital preservation and digital curation. In addition, format of digital resource is an important topic for research and courses.

Identification of Knowledge Structure of Pain Management Nursing Research Applying Text Network Analysis (텍스트네트워크분석을 적용한 통증관리 간호연구의 지식구조)

  • Park, Chan Sook;Park, Eun-Jun
    • Journal of Korean Academy of Nursing
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    • v.49 no.5
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    • pp.538-549
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    • 2019
  • Purpose: This study aimed to explore and compare the knowledge structure of pain management nursing research, between Korea and other countries, applying a text network analysis. Methods: 321 Korean and 6,685 international study abstracts of pain management, published from 2004 to 2017, were collected. Keywords and meaningful morphemes from the abstracts were analyzed and refined, and their co-occurrence matrix was generated. Two networks of 140 and 424 keywords, respectively, of domestic and international studies were analyzed using NetMiner 4.3 software for degree centrality, closeness centrality, betweenness centrality, and eigenvector community analysis. Results: In both Korean and international studies, the most important, core-keywords were "pain," "patient," "pain management," "registered nurses," "care," "cancer," "need," "analgesia," "assessment," and "surgery." While some keywords like "education," "knowledge," and "patient-controlled analgesia" found to be important in Korean studies; "treatment," "hospice palliative care," and "children" were critical keywords in international studies. Three common sub-topic groups found in Korean and international studies were "pain and accompanying symptoms," "target groups of pain management," and "RNs' performance of pain management." It is only in recent years (2016~17), that keywords such as "performance," "attitude," "depression," and "sleep" have become more important in Korean studies than, while keywords such as "assessment," "intervention," "analgesia," and "chronic pain" have become important in international studies. Conclusion: It is suggested that Korean pain-management researchers should expand their concerns to children and adolescents, the elderly, patients with chronic pain, patients in diverse healthcare settings, and patients' use of opioid analgesia. Moreover, researchers need to approach pain-management with a quality of life perspective rather than a mere focus on individual symptoms.